Airflow generating device

Abstract

An airflow generating device includes an airflow generating portion, a duct, and a controller. The airflow generating portion is configured to generate an airflow. The duct is configured to guide the airflow to a blowing outlet through which the airflow is blown out toward a passenger in a vehicle cabin. The controller is configured to cause the airflow to be intermittently blown out through the blowing outlet by controlling a frequency of a pulse voltage applied to the air flow generating portion and a duty ratio of a pulse width to a pulse period of the pulse voltage. The controller is configured to control the duty ratio and the frequency of the voltage such that the airflow is blown out through the blowing outlet at a speed between a predetermined lower limit, inclusive, and a maximum lower limit, non-inclusive, which is greater than the lower limit.

What is claimed is: 
     
         1 . An airflow generating device comprising:
 an airflow generating portion configured to generate an airflow;   a duct configured to guide the airflow generated by the airflow generating portion to a blowing outlet through which the airflow is blown out toward a passenger in a vehicle cabin; and   a controller configured to cause the airflow to be intermittently blown out through the blowing outlet by controlling a frequency of a pulse voltage applied to the air flow generating portion and a duty ratio of a pulse width to a pulse period of the pulse voltage, wherein   the controller is configured to control the frequency of the voltage and the duty ratio such that the airflow is blown out through the blowing outlet at a speed between a predetermined lower limit, inclusive, and a maximum lower limit, non-inclusive, which is greater than the lower limit.   
     
     
         2 . The airflow generating device according to  claim 1 , wherein
 the controller is configured to control the frequency of the pulse voltage between 0.5 Hertz and 20 Hertz.   
     
     
         3 . The airflow generating device according to  claim 1 , wherein
 the controller is configured to control the duty ratio within a particular range such that the airflow is intermittently blown out through the blowing outlet.   
     
     
         4 . The airflow generating device according to  claim 1 , wherein
 the controller is configured to:
 continuously blow out the airflow through the blowing outlet by controlling the duty ratio and the frequency of the pulse voltage applied to the airflow generating portion for a predetermined period from a start of operation; and then 
 intermittently blow out the airflow through the blowing outlet by controlling the duty ratio and the frequency of the pulse voltage applied to the airflow generating portion. 
   
     
     
         5 . A controller comprising:
 a processor; and   a memory coupled to the processor and storing instructions that when executed by the processor cause the processor to at least:
 control a blower to intermittently blow out an airflow through a blowing outlet toward a passenger in a vehicle cabin at a speed between a predetermined lower limit, inclusive, and a maximum lower limit, non-inclusive, which is greater than the lower limit by controlling (i) a frequency of a pulse voltage applied to the blower and (ii) a duty ratio of a pulse width to a pulse period of the pulse voltage. 
   
     
     
         6 . A method implemented by a processor, comprising:
 controlling a blower to intermittently blow out an airflow through a blowing outlet toward a passenger in a vehicle cabin at a speed between a predetermined lower limit, inclusive, and a maximum lower limit, non-inclusive, which is greater than the lower limit by controlling (i) a frequency of a pulse voltage applied to the blower and (ii) a duty ratio of a pulse width to a pulse period of the pulse voltage.